Ground Deformation Dataset for Geohazard Monitoring in the Central Ionian Islands (Greece) within the HOMEROS Project

1. Introduction

This dataset presents ground deformation measurements from the Central Ionian Islands (Greece) derived through Persistent Scatterer Interferometry (PSI) analysis within the framework of the HOMEROS project. The dataset is designed to support the detection, monitoring, and analysis of ground displacement over time, contributing to the assessment and mitigation of natural hazards such as earthquakes, landslides, floods, and subsidence.

The observations were obtained from Sentinel-1 Synthetic Aperture Radar (SAR) acquisitions provided by the European Space Agency’s Copernicus Programme. Data processing was carried out using the SNAPPING PSI service (Foumelis et al., 2022) ensuring reproducible and traceable workflows compliant with Open Science principles.

The dataset includes both ascending and descending line-of-sight (LOS) displacement products, as well as 3D decomposed components (East, Up) obtained through two independent decomposition methods.

The dataset will be updated every 6 months to ensure continued accessibility, interoperability, and reusability of the most recent ground-deformation observations from Sentinel-1 acquisitions. Each release will be published as a new Zenodo version under the same DOI, ensuring transparent versioning, long-term traceability, and consistent citation across updates.

2. Files

File naming conventions:

All files in this dataset follow a structured naming convention designed to convey essential metadata directly in the filename. For example:

homeros_ionian_snapping_psi_med_s1_a175_202201_202412_ref20220108.csv

refers to:

[project name][study area][processing algorithm][methodology][resolution][sensor or satellite mission][track/orbit descriptor][first qcquisition][last acquisition]_ref[reference acquisition date].[file extension]

The full dataset contains the following files:

• metadata_dictionary.csv: Descriptions of metadata fields.
• Ascending and Descending Line-of-Sight (LOS) products: Each geometry folder contains CSV files with displacement time series, GeoTIFF rasters representing mean velocity and coherence, and shapefile layers for geospatial visualization and corresponding metadata JSON files.
• 3D Decomposed Components (E-W and Up): Outputs from the grid-based and nearest-neighbor vector decomposition methods, provided at 50m and 100m spatial resolutions. Each subfolder contains displacement rasters and CSV tables for the respective 3D components, together with detailed metadata.

Total size: ~240 MB (compressed) / ~933 MB (uncompressed)

3. Dataset structure

Central_Ionian_dataset/
│
├── README.md
├── LICENSE.txt
│
├── ascending/
│   ├── homeros_ionian_snapping_psi_med_s1_a175_202201_202412_ref20220108.csv
│   ├── homeros_ionian_snapping_psi_med_s1_a175_202201_202412_ref20220108.tiff
│   ├── homeros_ionian_snapping_psi_med_s1_a175_202201_202412_ref20220108_coh.tiff
│   ├── homeros_ionian_snapping_psi_med_s1_a175_202201_202412_ref20220108.shp
│   ├── homeros_ionian_snapping_psi_med_s1_a175_202201_202412_ref20220108.dbf
│   ├── homeros_ionian_snapping_psi_med_s1_a175_202201_202412_ref20220108.prj
│   ├── homeros_ionian_snapping_psi_med_s1_a175_202201_202412_ref20220108.shx
│   └── metadata_ascending.json
│
├── descending/
│   ├── homeros_ionian_snapping_psi_med_s1_d080_202201_202412_ref20220102.csv
│   ├── homeros_ionian_snapping_psi_med_s1_d080_202201_202412_ref20220102.tiff
│   ├── homeros_ionian_snapping_psi_med_s1_d080_202201_202412_ref20220102_coh.tiff
│   ├── homeros_ionian_snapping_psi_med_s1_d080_202201_202412_ref20220102.shp
│   ├── homeros_ionian_snapping_psi_med_s1_d080_202201_202412_ref20220102.dbf
│   ├── homeros_ionian_snapping_psi_med_s1_d080_202201_202412_ref20220102.prj
│   ├── homeros_ionian_snapping_psi_med_s1_d080_202201_202412_ref20220102.shx
│   └── metadata_descending.json
│
└── 3d_components/
    ├── GRID/
    │   ├── 50/
    │   │   ├── homeros_ionian_snapping_psi_med_202201_202412_3d_decomp_grid50_ew.csv
    │   │   ├── homeros_ionian_snapping_psi_med_202201_202412_3d_decomp_grid50_up.csv
    │   │   ├── homeros_ionian_snapping_psi_med_202201_202412_3d_decomp_grid50_ew.tiff
    │   │   ├── homeros_ionian_snapping_psi_med_202201_202412_3d_decomp_grid50_up.tiff
    │   │   └── metadata_grid_50.json
    │   │
    │   └── 100/
    │       ├── homeros_ionian_snapping_psi_med_202201_202412_3d_decomp_grid100_ew.csv
    │       ├── homeros_ionian_snapping_psi_med_202201_202412_3d_decomp_grid100_up.csv
    │       ├── homeros_ionian_snapping_psi_med_202201_202412_3d_decomp_grid100_ew.tiff
    │       ├── homeros_ionian_snapping_psi_med_202201_202412_3d_decomp_grid100_up.tiff
    │       └── metadata_grid_100.json
    │
    └── NNV/
        ├── 50/
        │   ├── homeros_ionian_snapping_psi_med_202201_202412_3d_decomp_nnv50_ew.csv
        │   ├── homeros_ionian_snapping_psi_med_202201_202412_3d_decomp_nnv50_up.csv
        │   ├── homeros_ionian_snapping_psi_med_202201_202412_3d_decomp_nnv50_ew.tiff
        │   ├── homeros_ionian_snapping_psi_med_202201_202412_3d_decomp_nnv50_up.tiff
        │   └── metadata_nnv_50.json
        │
        └── 100/
            ├── homeros_ionian_snapping_psi_med_202201_202412_3d_decomp_nnv100_ew.csv
            ├── homeros_ionian_snapping_psi_med_202201_202412_3d_decomp_nnv100_up.csv
            ├── homeros_ionian_snapping_psi_med_202201_202412_3d_decomp_nnv100_ew.tiff
            ├── homeros_ionian_snapping_psi_med_202201_202412_3d_decomp_nnv100_up.tiff
            └── metadata_nnv_100.json

4. How to cite

5. References

Foumelis M, Delgado Blasco JM, Brito F, Pacini F, Papageorgiou E, Pishehvar P, Bally P. (2022). SNAPPING Services on the Geohazards Exploitation Platform for Copernicus Sentinel-1 Surface Motion Mapping. Remote Sensing, 14(23), 6075. https://doi.org/10.3390/rs14236075